The opinion of the Court was delivered by

This case is not, in the point now discussed, placed in a situation materially different from that which it presented on the former writ of error. It is urged that the present evidence of Dr Rose goes positively to show an agreement between him and Post, that the claims of Post should be applied in discharge of the mortgage, which the court below ought to have left to the jury; whereas, they charged that there was no evidence that could, in point of law, alter the character of these claims, and bar the operation of the Statute of Limitations upon them. Taking the testimony of Dr Rose alone, and without referring to the other evidence in the case, it is, in our opinion, too loose and uncertain in its character to justify the inference that any application of these claims had been made by the joint or concurrent acts of the parties prior to the assignment of the mortgage from Rose to Carmalt, so as to preclude the assignee from insisting on the bar by lapse of time. It is settled, that mutual debts do not per se extinguish each other. Himes v. Barnitz, (8 Watts 39); Carmalt v. Post, (8 Watts 406). To effect such extinguishment, there must be some act of the parties, whilst mutually debtor and creditor, by which they conclusively establish that one shall go in satisfaction of the other, which act must be of binding efficacy, so as to accompany the claims into whose soever hands they may pass, and fix definitively their character, and determine whether they still subsist as debts, or become cancelled and extinguished. *73But all that Dr Rose says is comprised in a line or two: that the unsettled accounts between them “ were to be applied on what the defendant owed for the land.” This apparently means that such was the purpose and intent of the parties, and that if either had requested the application to be made, it would not have been refused. But he does not allege that this was ever done; nor does he state that there was any positive and fixed agreement between them to that effect, which would conclude them, nor state when or where, or on what occasion such agreement was made. The design is left inchoate and incomplete, to be performed at some future day; and if before that day either party chooses to assign his claim to a third person, without having effected this purpose or intent, and without any express arrangement on the subject, the assignee might well contend, that what was intended to be done never was done, nor any act completed which would be equivalent in its legal operation. No'particular mode of making such application, either by endorsement or settlement of accounts, (though these, perhaps, would be the safest modes) is designated by law, but certainly there must be some positive and definite act or agreement by which both parties are bound, and not a floating general intention or willingness which either may relinquish, and which he must be considered as relinquishing who assigns his claim to a third person for a valuable consideration, and without notice, as appears to have been the case; otherwise third persons would be prejudiced by latent intentions in the breast of the assignor, never executed, and never communicated to them. For these reasons, we think there was no error in the charge of the court.

Judgment affirmed.